3117490

Information

• Patent Grant
• 3117490

• References
• Source

• Patent Number

  3,117,490

• Date Filed

  Not available

• Date Issued

  Tuesday, January 14, 1964
  60 years ago

• CPC

  • G01J1/1626 - Arrangements with two photodetectors, the signals of which are compared
  • G01J1/4219 - specially adapted for enlargers
  • G01J1/4223 - specially adapted for copy - or printing apparatus
  • G03B27/72 - Controlling or varying light intensity, spectral composition, or exposure time in photographic printing apparatus

• US Classifications

  • 355 - Photocopying
  • 250 - Radiant energy